Re: [PATCH v35 00/31] Introduce QC USB SND audio offloading support

From: Trilok Soni
Date: Wed Mar 05 2025 - 14:28:56 EST


On 3/5/2025 11:23 AM, Stephan Gerhold wrote:
> On Tue, Mar 04, 2025 at 02:46:28PM -0800, Wesley Cheng wrote:
>> On 3/4/2025 12:22 AM, Stephan Gerhold wrote:
>>> On Mon, Mar 03, 2025 at 06:39:52PM -0800, Wesley Cheng wrote:
>>>> On 2/19/2025 3:24 AM, Stephan Gerhold wrote:
>>>>> On Tue, Feb 18, 2025 at 04:47:23PM -0800, Wesley Cheng wrote:
>>>>>> Requesting to see if we can get some Acked-By tags, and merge on usb-next.
>>>>>>
>>>>>> Several Qualcomm based chipsets can support USB audio offloading to a
>>>>>> dedicated audio DSP, which can take over issuing transfers to the USB
>>>>>> host controller. The intention is to reduce the load on the main
>>>>>> processors in the SoC, and allow them to be placed into lower power modes.
>>>>>> There are several parts to this design:
>>>>>> 1. Adding ASoC binding layer
>>>>>> 2. Create a USB backend for Q6DSP
>>>>>> 3. Introduce XHCI interrupter support
>>>>>> 4. Create vendor ops for the USB SND driver
>>>>>>
>>>>>> USB | ASoC
>>>>>> --------------------------------------------------------------------
>>>>>> | _________________________
>>>>>> | |sm8250 platform card |
>>>>>> | |_________________________|
>>>>>> | | |
>>>>>> | ___V____ ____V____
>>>>>> | |Q6USB | |Q6AFE |
>>>>>> | |"codec" | |"cpu" |
>>>>>> | |________| |_________|
>>>>>> | ^ ^ ^
>>>>>> | | |________|
>>>>>> | ___V____ |
>>>>>> | |SOC-USB | |
>>>>>> ________ ________ | | |
>>>>>> |USB SND |<--->|QC offld|<------------>|________| |
>>>>>> |(card.c)| | |<---------- |
>>>>>> |________| |________|___ | | |
>>>>>> ^ ^ | | | ____________V_________
>>>>>> | | | | | |APR/GLINK |
>>>>>> __ V_______________V_____ | | | |______________________|
>>>>>> |USB SND (endpoint.c) | | | | ^
>>>>>> |_________________________| | | | |
>>>>>> ^ | | | ___________V___________
>>>>>> | | | |->|audio DSP |
>>>>>> ___________V_____________ | | |_______________________|
>>>>>> |XHCI HCD |<- |
>>>>>> |_________________________| |
>>>>>>
>>>>>
>>>>> As I noted on v34 [1], this version is still missing instructions and
>>>>> changes needed for testing this series. The device tree changes don't
>>>>> need to be part of the same series, but there should be at least a link
>>>>> provided to give other people the chance to provide Tested-by tags.
>>>>>
>>>>> IMO we shouldn't merge this series without those instructions, otherwise
>>>>> we risk that this just ends up being dead code that no one can use.
>>>>>
>>>>> Can you please share the device tree changes for a board upstream and
>>>>> any other changes needed to be able to test this series? E.g. for
>>>>> sm8250-mtp.dts, based on the examples in your cover letter.
>>>>>
>>>>
>>>> To clarify I'm testing this on sm8350 in recent times, but utilizing sm8250
>>>> definitions for the ASoC platform card, as the platform sound card is more
>>>> or less the same between the two SoCs. Back
>>>> when I started this series, sm8350 was missing a bunch of dependent
>>>> components, such as aDSP not being loaded, and missing platform sound card
>>>> definition, so I had to define and enable those on my own, which required a
>>>> slew of new DT nodes, hence why it wasn't as straight forward to include
>>>> the DT definitions yet for sm8350. Not thinking that this series would
>>>> take as long as it did, I was planning on separating out the DT changes in
>>>> a different series to enable offloading for the devices I have tested with.
>>>> (sm8150, sm8250 and sm8350)
>>>>
>>>> There's still a pretty big chunk of dependencies missing from sm8350, so
>>>> those would also be handled in the follow up DT submission. For now, its a
>>>> much bigger hurdle to get the main/functional changes in, and that was
>>>> taking a significant amount of time from my end to manage.
>>>>
>>>> If you want, I can give you the changes I have offline to enable this for
>>>> sm8350, since I haven't spent time formatting/prepping the changes for
>>>> submission yet.
>>>>
>>>
>>> Can you push it to a public branch somewhere (e.g. on CodeLinaro)? I was
>>> talking to some people from the community about testing this on some of
>>> the smartphones we have in upstream, so it wouldn't help if I just have
>>> the changes privately.
>>
>> Which CLO project/branch did you want me to push it to? Sorry, I haven't
>> worked too much with the CLO open branches. I have an account though.
>>
>
> Any project/branch is fine for me, I suggested CLO only because I
> assumed you already have an account there.
>
> You should be able to create a personal project and push it there. You
> could also use the fork button on
> https://git.codelinaro.org/linaro/linux/kernel/torvalds/linux to avoid
> having to push the full history yourself. It should result in a project
> similar to mine: https://git.codelinaro.org/stephan.gerhold/linux

Wesley - if not CLO, feel free to use the github. We can help you offline.

--
---Trilok Soni